/*
 * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/HttpException.java,v 1.19 2004/09/30 18:53:20 olegk Exp $
 * $Revision: 480424 $
 * $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $
 *
 * ====================================================================
 *
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.commons.httpclient;

import java.io.IOException;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.lang.reflect.Method;

/**
 * Signals that an HTTP or HttpClient exception has occurred.
 * 
 * @author Laura Werner
 * 
 * @version $Revision: 480424 $ $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov
 *          2006) $
 */
public class HttpException extends IOException {

	/**
	 * Creates a new HttpException with a <tt>null</tt> detail message.
	 */
	public HttpException() {
		super();
		this.cause = null;
	}

	/**
	 * Creates a new HttpException with the specified detail message.
	 * 
	 * @param message
	 *            the exception detail message
	 */
	public HttpException(String message) {
		super(message);
		this.cause = null;
	}

	/**
	 * Creates a new HttpException with the specified detail message and cause.
	 * 
	 * @param message
	 *            the exception detail message
	 * @param cause
	 *            the <tt>Throwable</tt> that caused this exception, or
	 *            <tt>null</tt> if the cause is unavailable, unknown, or not a
	 *            <tt>Throwable</tt>
	 * 
	 * @since 3.0
	 */
	public HttpException(String message, Throwable cause) {
		super(message);
		this.cause = cause;

		// If we're running on JDK 1.4 or later, tell Throwable what the cause
		// was
		try {
			Class[] paramsClasses = new Class[] { Throwable.class };
			Method initCause = Throwable.class.getMethod("initCause",
					paramsClasses);
			initCause.invoke(this, new Object[] { cause });
		} catch (Exception e) {
			// The setCause method must not be available
		}
	}

	/**
	 * Return the <tt>Throwable</tt> that caused this exception, or
	 * <tt>null</tt> if the cause is unavailable, unknown, or not a
	 * <tt>Throwable</tt>.
	 * 
	 * @return the <tt>Throwable</tt> that caused this exception, or
	 *         <tt>null</tt> if the cause is unavailable, unknown, or not a
	 *         <tt>Throwable</tt>
	 * 
	 * @since 3.0
	 */
	public Throwable getCause() {
		return cause;
	}

	/**
	 * Print this HttpException and its stack trace to the standard error
	 * stream.
	 * 
	 * @since 3.0
	 */
	public void printStackTrace() {
		printStackTrace(System.err);
	}

	/**
	 * Print this HttpException and its stack trace to the specified print
	 * stream.
	 * 
	 * @param s
	 *            the <tt>PrintStream</tt> to which the exception and its stack
	 *            trace should be written
	 * 
	 * @since 3.0
	 */
	public void printStackTrace(PrintStream s) {
		try {
			// JDK 1.4 has a nice printStackTrace method that prints the cause's
			// stack
			// trace too and prunes out duplicate stack frames. Call it if
			// possible,
			// which is determined by checking whether JDK 1.4's getStackTrace
			// method is present
			Class[] paramsClasses = new Class[] {};
			this.getClass().getMethod("getStackTrace", paramsClasses);
			super.printStackTrace(s);
		} catch (Exception ex) {
			// If that didn't work, print it out ourselves
			// First print this exception's stack trace.
			super.printStackTrace(s);
			if (cause != null) {
				// Print out the exception that caused this one.
				// This will recurse if the cause is another HttpException.
				s.print("Caused by: ");
				cause.printStackTrace(s);
			}
		}
	}

	/**
	 * Print this HttpException and its stack trace to the specified print
	 * writer.
	 * 
	 * @param s
	 *            the <tt>PrintWriter</tt> to which the exception and its stack
	 *            trace should be written
	 * 
	 * @since 3.0
	 */
	public void printStackTrace(PrintWriter s) {
		try {
			// JDK 1.4 has a nice printStackTrace method that prints the cause's
			// stack
			// trace too and prunes out duplicate stack frames. Call it if
			// possible,
			// which is determined by checking whether JDK 1.4's getStackTrace
			// method is present
			Class[] paramsClasses = new Class[] {};
			this.getClass().getMethod("getStackTrace", paramsClasses);
			super.printStackTrace(s);
		} catch (Exception ex) {
			// If that didn't work, print it out ourselves
			// First print this exception's stack trace.
			super.printStackTrace(s);
			if (cause != null) {
				// Print out the exception that caused this one.
				// This will recurse if the cause is another HttpException.
				s.print("Caused by: ");
				cause.printStackTrace(s);
			}
		}
	}

	/**
	 * Sets the text description of the reason for an exception.
	 * 
	 * @param reason
	 *            The reason for the exception.
	 * 
	 * @deprecated HttpClient no longer uses this for itself. It is only
	 *             provided for compatibility with existing clients, and will be
	 *             removed in a future release.
	 */
	public void setReason(String reason) {
		this.reason = reason;
	}

	/**
	 * Get the text description of the reason for an exception.
	 * 
	 * @deprecated HttpClient no longer uses this for itself. It is only
	 *             provided for compatibility with existing clients, and will be
	 *             removed in a future release.
	 */
	public String getReason() {
		return reason;
	}

	/**
	 * Sets the status code description of the reason for an exception.
	 * 
	 * @param code
	 *            The reason for the exception. This is intended to be an HTTP
	 *            status code.
	 * 
	 * @deprecated HttpClient no longer uses this for itself. It is only
	 *             provided for compatibility with existing clients, and will be
	 *             removed in a future release.
	 */
	public void setReasonCode(int code) {
		reasonCode = code;
	}

	/**
	 * Get the status code description of the reason for an exception.
	 * 
	 * @deprecated HttpClient no longer uses this for itself. It is only
	 *             provided for compatibility with existing clients, and will be
	 *             removed in a future release.
	 */
	public int getReasonCode() {
		return this.reasonCode;
	}

	/**
	 * A "reason" string provided for compatibility with older clients.
	 * 
	 * @deprecated HttpClient no longer uses this field for itself. It is only
	 *             provided for compatibility with existing clients.
	 */
	private String reason;

	/**
	 * Reason code for compatibility with older clients.
	 * 
	 * @deprecated HttpClient no longer uses this field for itself. It is only
	 *             provided for compatibility with existing clients.
	 */
	private int reasonCode = HttpStatus.SC_OK;

	/** The original Throwable representing the cause of this error */
	private final Throwable cause;
}
